JPH044260Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to an improvement of a pilot type hydraulic control valve.

Prior art and its problems A type of pilot-type hydraulic control valve includes a control valve element that is movably provided within a valve body and is driven by pilot hydraulic pressure against the biasing force of a return spring, and a control valve that is opened by a plug. There is a type of valve that is provided in the valve body so as to be oil-tightly closed, and has a pilot oil chamber that applies the pilot oil pressure to one end of the valve element. In this type of hydraulic control valve, a return spring is usually provided on the side opposite to the pilot oil chamber so as to bias the control valve element toward the pilot oil chamber, and the return spring is also installed on the side opposite to the pilot oil chamber to maintain the pilot oil pressure at a predetermined constant level. An independent safety valve was provided to open the pilot oil chamber to drain when the pressure was exceeded. For this reason, the pilot type hydraulic control valve as a whole becomes large, which is an important problem especially when it is mounted on a vehicle as a hydraulic control valve for an automatic transmission.

Means for Solving the Problems The present invention was developed against the background of the above-mentioned circumstances, and its gist is that it is movably provided within the valve body and that the biasing force of the return spring is applied by pilot hydraulic pressure. and a pilot oil chamber, which is provided in the valve body and whose opening is oil-tightly closed by a plug, and which applies the pilot hydraulic pressure to one end of the valve element. In the pilot type hydraulic control valve, the return spring is accommodated in the pilot oil chamber, and one end of the return spring is received by the plug, and
A safety valve is provided in the plug to open the pilot oil chamber to drain when the pilot oil pressure exceeds a predetermined constant pressure.

Function and Effect of the Invention With this method, the safety valve, which was conventionally provided independently, is provided inside the plug, and the return spring, which was conventionally provided on the opposite side of the pilot oil chamber, is housed in the pilot oil chamber. , the valve body of the pilot type hydraulic control valve becomes smaller. Therefore, especially when a plurality of automatic transmissions of a vehicle are provided for hydraulic control, there is an advantage that the automatic transmissions can be made smaller and lighter.

Embodiment FIG. 1 shows a line oil passage 12 from a hydraulic pump 10.
A pilot pressure control valve 14 for regulating the working hydraulic pressure, that is, the line hydraulic pressure, which is pumped through the
It shows. In the figure, the valve body 16 is formed with a non-penetrating stepped hole consisting of a large diameter part 18 and a small diameter part 20, and a spool-shaped control valve element 22 is movable in the axial direction in the small diameter part 20. It is fitted. The small diameter portion 20 includes an inflow port 24 that communicates with the line oil passage 12 and an inflow port 24 that communicates with the line oil passage 12.
A pair of discharge ports 26 and 28 for discharging the hydraulic oil in 2 are communicated with each other, and as the control valve 18 moves, an opening between the inflow port 24 and the pair of discharge ports 26 and 28 opens. can now be changed.

An introduction chamber 30 is provided at the end of the small diameter portion 20, and a line hydraulic pressure for acting on the end face of the control valve 22 is supplied to the introduction chamber 30 through a passage 32 formed in the control valve 22. is being introduced. Further, a passage 36 is formed in the valve body 16 and includes an orifice 34 and communicates with the inflow port 24.
is connected to a solenoid valve 40 via a filter 38, and also to a pilot oil chamber 42 formed within the large diameter portion 18. Above solenoid valve 4
0 is proportionally driven or due-day driven to change the pilot oil pressure by letting the hydraulic oil supplied through the filter 38 escape to the drain.

The pilot oil chamber 42 is constructed by fitting a plug 44 oil-tightly into the opening of the large diameter portion 18. A return spring 48 in the form of a compression coil is inserted between them to urge the control valve element 22 toward the introduction chamber 30 side. A safety valve 50 is provided within the plug 44.

That is, the plug 44 is formed with a housing hole 54 that opens to the outside and communicates with the pilot oil chamber 42 through the pore 52 at the bottom. 5
6. A spring 60 that biases the spherical valve element 56 in the valve closing direction via the pressing member 58 is housed.
This spring 60 is screwed into the opening of the accommodation hole 54 and is attached to an adjustment member 64 in which a through hole 62 is formed.
It is accepted by. A lock nut 66 is screwed onto the adjusting member 64, so that the adjusting member 64 is fixed at a desired axial position.

In the pilot pressure control valve 14 configured as described above, the control valve element 22 operates in the valve opening direction based on the line oil chamber in the introduction chamber 30 and in the valve closing direction based on the pilot oil pressure and the biasing force of the return spring 48. As the pilot oil pressure is changed by the operation of the solenoid valve 40, the flow rate of operating oil released from the line oil passage 12 to the drain is changed, and the line oil pressure is increased. Pressure is regulated. Further, when the pilot oil pressure exceeds a predetermined constant value, the spherical valve element 56 is moved against the urging force of the spring 60, so that the safety valve 50 is opened. As a result, the hydraulic oil in the pilot hydraulic pressure 42 is released through the small hole 52 and the through hole 62, so that an excessive increase in the pilot hydraulic pressure is prevented.

Here, the pilot type pressure control valve 1 of this embodiment
4, as mentioned above, the return spring 48
is housed in the pilot oil chamber 42, and
Since the safety valve 50 is disposed within the plug 44 that seals the pilot oil chamber 42 in an oil-tight manner, it is different from the conventional pilot type in which the return spring is disposed on the opposite side of the pilot oil chamber or the safety valve is disposed independently. Compared to hydraulic control valves, it is significantly smaller in size. For this reason, for example, when a plurality of pilot type hydraulic control valves of the type of this embodiment are mounted on a vehicle for hydraulic control of an automatic transmission, the automatic transmission becomes smaller and lighter.

The above-mentioned embodiment is merely an embodiment of the present invention, and various modifications may be made to the present invention without departing from the spirit thereof. For example, although a pilot type pressure control valve is described in the above embodiment, a pilot type flow control valve or the like may also be used.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating the configuration of an embodiment of the present invention. 16... Valve body, 22... Control valve, 4
2...Pilot oil chamber, 44...Plug, 50...
…safety valve.

Claims (1)

[Scope of Claim for Utility Model Registration] A control valve element that is movably provided within the valve body and is driven by pilot hydraulic pressure against the biasing force of a return spring, and an opening that is oil-tightly closed by a plug. A pilot type hydraulic control valve is provided in the valve body and includes a pilot oil chamber for applying the pilot oil pressure to one end of the valve element, wherein the return spring is accommodated in the pilot oil chamber and A pilot characterized in that a plug receives one end of the return spring, and a safety valve is provided in the plug to open the pilot oil chamber to a drain when the pilot oil pressure exceeds a predetermined constant pressure. type hydraulic control valve.